“Abnormalities in regional cerebral blood flow (rCBF) have been reported to characterize depressive episodes; they are at least partly reversed by antidepressant treatment. We explored the changes in rCBF induced by vagus nerve stimulation (VNS), a recently proposed antidepressant strategy. Decreases of rCBF in the amygdala, left hippocampus, left subgenual cingulate cortex, left and right ventral anterior cingulum, right thalamus and brain stem were observed; the only increase of rCBF was found by SPM analysis in the middle frontal gyrus. This pattern shares features with changes of rCBF previously associated with the administration of selective serotonin reuptake inhibitors. Similarities to other brain-stimulation strategies in antidepressant treatment were less pronounced.”

Compared with baseline values in the HAMD scale (mean 23.7; SD 2.4), there was a significant (t=14.5; df=8; p<0.001) improvement in symptoms after 12 months' stimulation (mean 10.2; SD 2.4). The duration of hospitalisation dropped on average by 20 days in the first post-implantation year, the treatment frequency from 33 to 14 visits, and drug treatment from 4 to an average of 3 psychotropic drugs.

CONCLUSION:

In addition to an improvement in clinical symptoms, the VNS method might enable an amortisation of costs.

Both noninvasive transcutaneous and invasive direct vagus nerve stimulations significantly suppressed spreading depression susceptibility in the occipital cortex in rats. The electrical stimulation threshold to evoke a spreading depression was elevated by more than 2-fold, the frequency of spreading depressions during continuous topical 1 M KCl was reduced by ∼40%, and propagation speed of spreading depression was reduced by ∼15%. This effect developed within 30 minutes after vagus nerve stimulation and persisted for more than 3 hours. Noninvasive transcutaneous vagus nerve stimulation was as efficacious as direct invasive vagus nerve stimulation, and the efficacy did not differ between the ipsilateral and contralateral hemispheres. Our findings provide a potential mechanism by which vagus nerve stimulation may be efficacious in migraine and suggest that susceptibility to spreading depression is a suitable platform to optimize its efficacy.

literature

Our autonomic nervous system (ANS) is a control system that acts largely unconsciously and is responsible for the regulation many of our bodily functions. Is has two branches that work in opposition to one another to create a balance, these are the parasympathetic nervous system and the sympathetic nervous system.

The sympathetic nervous system is often considered the 'fight or flight' system, while the parasympathetic is referred to as the 'rest and digest' system. Many serious health conditions have been linked to an overactive sympathetic nervous system (high stress), where the ANS is out of balance.

The vagus nerve is linked to the parasympathetic branch of the ANS and by stimulating it, it is possible to reduce sympathetic activity and restore natural balance in the body needed for optimal health.